Liquid filter assembly; and methods

ABSTRACT

A liquid filter assembly is provided. The preferred assembly includes a serviceable filter cartridge having a primary filter section and a secondary or bypass filter section. The preferred assembly includes a bypass valve arrangement and a suction filter arrangement. The suction filter arrangement preferably includes a dimensionally biased valve arrangement, preferably one which is devoid of a helical coiled spring, to control flow through the suction filter. A flow/pressure regulation valve, to allow flow from an interior of the assembly to a reservoir if needed, is preferably provided. Preferred serviceable filter cartridges are shown.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a National Stage Application of PCT/US2004/043227,filed Dec. 21, 2004, for which priority is claimed to the U.S.Provisional Application of Ser. No. 60/532,761, filed Dec. 22, 2003 andwhich application(s) are incorporated herein by reference. A claim ofpriority to both, to the extent appropriate is made.

FIELD OF THE INVENTION

The invention relates generally to liquid filters and methods. Exampleembodiments described, are in-tank filters, for use, for example, in ahydraulic system.

BACKGROUND OF THE INVENTION

Liquid filters are employed in a variety of applications, including, forexample, hydraulic systems, fuel systems and engine lubrication systems.

In general, liquid filters which accommodate downstream components, areof concern. Particularly, it is of concern to prevent cavitation ofpumps and other equipment downstream from liquid filters. Conditionssuch as cold starts, flow surges or occluded elements can result indamaged downstream components. Improvements are desirable.

SUMMARY OF THE INVENTION

Liquid filter assemblies are provided. The liquid filter assemblieseach, include a housing and a suction filter assembly. The housingdefines an interior and includes a liquid flow inlet arrangement, aliquid flow outlet arrangement, and a tank reservoir liquid flowinlet/outlet. The suction filter assembly is secured to the housing andis positioned in liquid flow communication with the tank reservoirliquid flow inlet/outlet. The suction filter assembly preferablyincludes an extension of suction filter media defining a central volume;and, a first, non-helical spring, directionally biased valve arrangementpositioned in operative association with the suction filter media. Inone example embodiment, the non-helical spring, directionally biasedvalve arrangement is located within the central volume defined by thesuction filter media. In another example embodiment, it surrounds thesuction filter media.

The first, non-helical spring, directionally biased valve arrangement isgenerally positioned and configured to readily permit liquid flow from atank reservoir into the housing interior. The first, non-helical spring,directionally biased valve arrangement is also configured to resistliquid flow from the housing interior through the first, non-helicalspring, directionally biased valve arrangement.

In a typical embodiment, the first, non-helical spring, directionallybiased valve arrangement comprises a valve sheet having at least one cutvalve therein. A typical valve sheet would comprise a valve ring-shapedmember having at least one and typically a plurality of cut valves, forexample flap valves, therein. Typical flap valves would be u-shaped flapvalves, for example curved u-shape flap valves or boxed u-shape flapvalves. Typically, the valve sheet is positioned adjacent a support thathas at least one flow aperture therein.

A typical embodiment preferably further includes a flow/pressureregulation valve or valve assembly. For certain applications theflow/pressure regulation valve is positioned at a location surrounded bythe suction filter media and in a position configured to regulate andselectively release flow from the housing interior to a reservoir, as aresult of liquid flow passage through the reservoir liquid flowinlet/outlet. In another embodiment, a valve closure member of theflow/pressure regulation valve is positioned at a location at an end ofthe assembly, not specifically surrounded by the suction filter media.

In certain of the embodiments shown the flow/pressure regulation valveassembly comprises a slidable valve member, a biasing member such as aspring, and a valve seat having an aperture therein. Several variationsof this are depicted.

Preferred configurations for components of, or useable in, theassemblies are provided. For example, preferred suction filterassemblies are provided. Also, preferred serviceable filter cartridgearrangements, useable in the liquid filter assemblies are provided.

The preferred filter cartridge includes: a primary filter cartridgesection and a bypass filter cartridge section secured to one another;and, a first end cap. In the preferred embodiments, the primary filtercartridge section and bypass filter cartridge section are on oppositesides of the first end cap. Also positioned at the first end cap, is aseal arrangement for providing a seal with a central tube, for example astand pipe or other structure, in the assembly with which the filtercartridge is used.

A second end cap for the filter cartridge, positioned in an opposite endof the primary filter cartridge section from the first end cap, includesa seal mount thereon. In one embodiment, the seal mount defines a sealplane extending at a non-orthogonal angle to a central axis of theprimary filter cartridge section. When this non-orthogonal mount isused, preferably the seal plane defines an acute angle with the centralaxis within the range of 30-60°, inclusive; the term “inclusive” in thiscontext meaning that the end points are included in the range. Inanother embodiment, the seal mount on the second end cap is positionedin a plane orthogonal to a central axis of the primary filter cartridgesection. In this latter arrangement, preferably the second end capincludes an axially projecting tube, and the seal is mounted on anoutside of this tube.

The preferred filter cartridge includes a third end cap, positioned atan opposite end of the bypass filter section from the first end cap. Thethird end cap can include an optional outwardly projecting contaminantcollection arrangement thereon. An optional variation with a seal memberis also shown.

Methods of assembly and use are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, partially cross-sectional, diagram depicting afirst embodiment of a fluid filter arrangement, according to the presentdisclosure.

FIG. 1A is an enlarged fragmentary view of a portion of FIG. 1.

FIG. 1B is a cross-sectional view of a component useable in theembodiment of FIG. 1.

FIG. 1C is an enlarged, partially cross-sectional view of the componentof FIG. 1B, having a bypass valve assembly mounted therein.

FIG. 1D is an exploded perspective view of the assembly depicted in 1C.

FIG. 2 is a schematic diagram illustrating one example of operation of aliquid filter arrangement, according to the present disclosure.

FIG. 3 is an enlarged, fragmentary, cross-sectional view of a portion ofFIG. 1.

FIG. 3A is an exploded perspective view of an assembly depicting analternative to selected features depicted in FIG. 3.

FIG. 3B is a partially cross-sectional side elevational view of theassembly of FIG. 3A.

FIG. 4 is a view analogous to FIG. 3, of an alternate assembly usablewith the arrangement of FIG. 1.

FIG. 5 is a depiction of a collection of components that can beassembled to provide a subassembly usable in an arrangement according tothe principles of FIG. 1.

FIG. 6 is a partially cross-sectional side elevational view of acomponent of the assembly depicted in FIGS. 3A and 3B.

FIG. 7 is a schematic exploded perspective view of the assembly of FIG.6.

FIG. 8 is a partially cross-sectional side elevational view of acomponent of the assembly depicted in FIGS. 6 and 7.

FIG. 9 is a cross-sectional view of an alternate filter replacement partfor the assembly of FIG. 1.

FIG. 10 is a side perspective view of an alternate filter assemblyaccording to the present disclosure.

FIG. 11 is a partially cross-sectional side view of the assemblydepicted in FIG. 10.

FIG. 12 is an enlarged fragmentary view of the assembly depicted in FIG.11.

FIG. 13 is a flow chart depicting operation of the assembly of FIG. 10.

FIG. 14 is a perspective view of a cover piece for the assembly of FIG.10.

FIG. 15 is a side cross-sectional view of the cover piece depicted inFIG. 14, taken along line 15-15.

FIG. 16 is a perspective view of a filter head component of the assemblydepicted in FIG. 10.

FIG. 17 is a perspective view of a sidewall component useable in theassembly of FIG. 10.

FIG. 18 is a partially cross-sectional side view of the sidewallcomponent of FIG. 17, shown without a handle mounted thereon.

FIG. 19 is a perspective view of a replacement part filter cartridgeuseable in the assembly of FIG. 10.

FIG. 20 is an enlarged partially cross-sectional side elevational viewof the replacement part filter cartridge of FIG. 19.

FIG. 21 is a top perspective view of a component useable in the assemblyof FIG. 10.

FIG. 22 is a bottom perspective view of the component depicted in FIG.21.

FIG. 23 is a cross-sectional view of the component depicted in FIG. 21.

FIG. 24 is a side elevational view of a suction filter and non-helicalspring, directionally biased valve arrangement, configured as asub-assembly for useable in the arrangement of FIG. 10.

FIG. 25 is a cross-sectional view of the sub-assembly of FIG. 24.

FIG. 26 is a schematic, cross-sectional view taken along line 26-26,FIG. 24.

FIG. 27 is a cross-sectional view of the frame piece depicted in FIGS.21-23, shown with valve member 751 mounted thereon and depicted in aclosed position.

FIG. 28 is a view analogous to FIG. 27, showing the valve member in anopen position.

FIG. 29 is an exploded schematic view of a non-helical spring valvearrangement useable for the suction valve assembly described herein forFIGS. 10 and 11.

DETAILED DESCRIPTION I. A First Example Embodiment; FIGS. 1-9

The reference numeral 1, FIG. 1, generally indicates a liquid filterarrangement or assembly according to one embodiment of the presentdisclosure. In FIG. 1, the assembly 1 is depicted in an ordinaryorientation for use. Herein the terms “top,” “bottom,” “above,” and“below” are sometimes used to characterize the relative positions ofcomponents. When these terms are used, reference is meant to theorientation of FIG. 1, i.e., the typical orientation of use for theassembly 1.

The liquid filter assembly 1 includes a housing 3: comprising a filterhead 4 having a body 4 a and a removable top or cover 5; and, a sidewall 7, which in use depends from filter head 4. In general, the housing3 defines an internal volume 8, in which: selected internal componentryas defined is contained; and, certain filtering and flow operations, asdescribed herein below, occur. The liquid filter assembly 1 furtherincludes a suction filter assembly 10, as defined herein.

The liquid filter assembly 1 includes, operably positioned therein, aserviceable filter cartridge arrangement 15. By the term “serviceable”in this context, it is meant that the filter cartridge 15 is removableand replaceable; i.e., it can be removed from the liquid filterarrangement 1, and be refurbished or be replaced, periodically, asdesired. For the particular, preferred, liquid filter arrangement 1shown, the serviceable filter cartridge 15 optionally includes twofilter sections or components namely: a primary filter cartridge orcartridge section 17; and, a bypass filter cartridge or cartridgesection 18. For the particular liquid filter assembly 1 depicted, theprimary filter cartridge section 17 and bypass filter cartridge section18 are secured to one another, and thus are removed and are serviced asan integral unit.

Arrangements are feasible, using selected ones of the principlesdisclosed herein, in which the primary filter cartridge or cartridgesection 17 is not integrally attached to the bypass filter cartridge orcartridge section 18. However, the arrangement depicted, in which thetwo are permanently secured to one another (or are integral), isconvenient and preferred.

The preferred serviceable filter cartridge assembly 15 further includes,as described below, an end cap and seal arrangement 20, which providesfor a preferred mounting and sealing of the serviceable filter cartridgearrangement 15, within the liquid filter arrangement 1.

The preferred liquid filter assembly 1 depicted includes a bypass valveassembly 25, described below.

With respect to the assemblies described herein, in some instancesreference will be made to “filtering flow.” The term “filtering flow” inthis context, is meant to refer to a flow which occurs with passagethrough media, to provide filtering to the liquid involved in the flow.Alternatively, in some instances reference will be made to“non-filtering” flow. The term “non-filtering” in this context, is meantto refer to a flow between locations, which does not involve passagethrough a filter media.

Referring still to FIG. 1, typical operation of the various componentsdefined, will be understood from the following. The filter head 4generally includes a filter body 4 a having an inlet or inletarrangement 30 and an outlet or outlet arrangement 31. Herein, theliquid flow inlet arrangement 30 will sometimes be referred to as acirculation loop liquid flow inlet arrangement, since it is an inlet tothe filter head 4 of liquid from a circulation loop in which the liquidcirculates to perform its function. Similarly the outlet arrangement 31will sometimes be referred to as a circulation loop liquid flow outletarrangement, since it is an outlet for filtered liquid, from the filterhead 4 and thus the assembly 1, for the liquid to be directed into acirculation loop to perform its function. In both instances, the termsare meant to distinguish an inlet/outlet arrangement, discussed below,referenced as the tank or reservoir inlet/outlet, which provides forliquid flow from the assembly 1 directly into a liquid reservoir or tankreservoir.

The particular assembly 1 depicted, has a single inlet aperture forinlet arrangement 30, and a single outlet aperture for outletarrangement 31. It is noted that the inlet arrangement 30 could comprisemultiple inlet apertures; and/or, the outlet arrangement 31 couldcomprise multiple outlet apertures. This would be a function of thenumber of hydraulic lines or circulation lines necessary, for theequipment in which assembly 1 is used.

Liquid to be filtered is directed into inlet arrangement 30 in thedirection of arrow 30 a. The unfiltered liquid then flows into annularunfiltered liquid volume 33, around the serviceable filter cartridgeassembly 15. In general, volume 33 is referred to as an “unfilteredliquid volume,” since the liquid received therein, will generally bereceived directly from a circulation loop, and will be unfiltered andrequire filtering. Referring to FIG. 1, it is noted that for theassembly 1 depicted, volume 33 can be considered to have three generalregions: upper region 33 a which is immediately surrounded by a portionof the filter head body 4 a; middle region 33 b which positioned betweenthe housing side wall 7 and the primary filter cartridge or cartridgesection 17; and, lower region 33 c which is positioned between thehousing side wall 7 and the bypass filter cartridge section 18.

In normal operation, from the unfiltered liquid volume 33, the liquid ispassed through the primary filter cartridge 17 in the general directionsof arrows 34, into central volume 35 defined by the serviceable filtercartridge 15. (This would be a filtering flow.) From the central volume35 the liquid can pass out of the filter cartridge 15 in a direction ofarrow 40 to outlet 31, and outwardly from the assembly 1 in thedirection of arrow 41. (The flow from volume 35 through outlet 31 is anon-filtering flow.)

The operation described thus far is a normal operation in which theprimary filter cartridge 17 has not been substantially occluded; and,the flow demands of the circulation loop or system in which the liquidfilter assembly 1 is positioned are relatively constant both upstreamand downstream of the liquid filter arrangement 1. Herein, the flow pathindicated by arrow 30 a and arrow 41, is generally referenced as acirculation loop for the operation of the equipment involved. Withinthat loop there may be a variety of pumps, valves and mechanicalequipment to be operated. The invention in part concerns providingvarious mechanical arrangements within liquid filter assembly 1, toensure that an appropriate level of fluid, and flow of fluid, in thatcirculation loop is maintained.

To address the event that liquid flow demands in the circulation loopdownstream of the assembly 1, i.e., in the direction of arrow 41, arenot sufficiently great to require all filtered liquid entering in path30 a to be directed into the circulation loop by passage (afterfiltering) through outlet 31, an alternate flow direction is provided.In particular, flow from central volume 35 can be directed outwardlyfrom the housing side wall 3, and eventually outwardly from the assembly1 and into a reservoir, by passage through a housing reservoiroutlet/inlet 42. The term “outlet/inlet” (or alternatively“inlet/outlet”) in this context, is meant to indicate that the passageway 42 is configured to allow flow from housing 7 to exit to thereservoir, or flow to enter housing 7 from the reservoir, depending onoperating circumstances. This is described in greater detail below. Thetypical reservoir is a tank reservoir, as referenced below.

More specifically, for the assembly 1 depicted, flow from the centralvolume 35 can be directed through a tube or center stand pipe 45, inparticular through central flow channel 45 a in the stand pipe 45, inthe direction of arrow 46 through flow/pressure regulation arrangement47 and outwardly from the assembly 1 by passage through outlet 48 of thesuction filter assembly 10, in the direction of arrow 49. (Flow fromvolume 35 through outlet 48 is a non-filtering flow.)

In a typical operation, the flow path indicated by arrow 49 would be aliquid flow exit from assembly 1 into a reservoir tank, not shown inFIG. 1. In typical use, although alternatives are possible, a liquidfilter assembly 1 in accord with the principles described herein, wouldbe mounted on a reservoir tank with suction filter assembly 10 submergedin the reservoir. Such arrangements are sometimes referred to as“in-tank” assemblies.

With the particular, preferred, liquid filter assembly 1 depicted,flow/pressure regulation valve arrangement 47 is conveniently positionedwithin the suction filter assembly 10, as described in detail below,although alternatives are possible.

From the above descriptions, it can also be expected that in somecircumstances, there may be a flow demand increase downstream of theliquid filter arrangement 1, relative to the liquid volume and flowgoing into inlet arrangement 30. When this occurs, liquid will be drawnfrom the reservoir in the directions of arrows 50, eventually throughthe housing reservoir inlet/outlet 42 into central volume 35. Such aflow will generally be through suction filter 51, in suction filterarrangement 10, and is a filtering flow. A directionally biased valvearrangement 54, preferably as described in detail below, is provided inthe suction flow path. The directionally biased valve arrangement 54allows for entrance of liquid into region 35, but inhibits liquid flowin an opposite direction, so as not to override or disable or properbypass operation of flow/pressure regulation valve arrangement 47. Thepreferred directionally biased valve arrangement 54 depicted, is anon-helical spring, valve arrangement. By the term “non-helical spring”in this context, it is meant that the valve closure pressure is notprovided by a helical, coiled, spring. This is preferred, for convenientoperation and assembly. A particular, convenient, non-helical spring,valve arrangement, is described in detail below.

To protect the equipment in the circulation loop, in circumstances inwhich the primary filter cartridge section 17 becomes occluded to anundesirable level, a bypass filter arrangement 55 is provided. Thebypass filter arrangement 55 includes bypass filter 18 and bypasscontrol valve arrangement 25. In general, should the pressuredifferential across media 17 a in primary filter cartridge section 17(outside or unfiltered side 17 b to inside or filtered side 17 c) becomesufficiently high, the bypass control valve 25 is configured to open, toallow liquid flow through bypass filter media 18 a in cartridge section18 and into central volume 35, as a filtering flow but without passagethrough filter media 17 a in primary filter cartridge section 17. Thisflow can then proceed, in the direction of arrow 40, FIG. 1, throughoutlet arrangement 31, or into the reservoir by passage throughreservoir inlet/outlet 42 and then from assembly 1 via the pathway ofarrow 49. (A liquid pressure differential that opens the bypass valvewill sometimes be referenced as a “bypass valve liquid openingpressure.”)

Now that the basic operation, and general components, of the liquidfilter assembly 1 are understood, a more detailed examination will bemade of selected component parts. Attention is first directed to thefeatures of the housing 3. For a typical liquid filter assembly 1,filter head 4 will be a cast member, for example made from cast aluminumor other material. Cover 5 is threadably secured to the filter head 4,to close service aperture 5 a, with a seal provided by o-ring 60. Thecover 5 includes an outer, nut shaped, projection 61 for engagement by awrench or other tool.

Although alternatives are possible, the cover 5 includes, positionedinternally and centrally, a stem 62, configured to project into acentral volume 4 b of filter head 4. In use, the stem 62 is positionedand sized to press against an upper most portion 15 a of a serviceablefilter cartridge 15 positioned internally of the housing 3, to ensurethat the serviceable filter cartridge 15 is positioned, in extensioninto the housing 3, at an appropriate position and, to ensure that thecartridge 15 cannot be moved out of its operational (sealed) position.This will be described below in more detail, in connection with thefilter cartridge 15.

The side wall portion 7 of the liquid filter assembly 1 depicted, isseparable from the filter head 4. In particular, the body 4 a of filterhead 4 includes an aperture 63 therein positioned on opposite side ordirection of the filter head body 4 a from the service aperture 5 a andcover 5. The sidewall section 7, projects through, and outwardly from(in use downwardly from), the aperture 63.

The sidewall section 7, is depicted in FIG. 1C. Although alternativesare possible, in a preferred arrangement, FIG. 1C, the side wall section7 comprises a molded plastic component having a shoulder 64 (at an upperend in use) and an opposite (in use bottom) end 65. The side wallsection 7 includes a projecting tube 66 which defines the reservoirinlet/outlet 42. In preferred arrangements of the type depicted in FIG.1, tube 66 will typically have a smaller cross-sectional area, than sidewall section 7 a. In a typical embodiment, the side wall section 7 a andtube 66 will be circular in cross section, with a diameter of tube 66being at least 10%, typically at least 25% and usually at least 30%,smaller than region 7 a of side wall section 7 located above end 65. (Itis noted that the sidewall portion 7, FIG. 3, differs from thearrangement of FIG. 1 with respect to specific features for attachmentto assembly 10. This is discussed below.)

As will be apparent from the descriptions below, the smaller diameter oftube 66 relative to side wall section 7 a, provides that a suctionfilter assembly 10 can be attached, to the tube 66, without an overallresulting diameter being generated that is larger than aperture 63. Thisallows for convenient assembly, as discussed below.

The side wall 7 is sized such that, during assembly, when the top 5 isremoved from body 4 a, FIG. 1, the side wall 3 can be pushed into thehousing 3 through the opening 5 a provided by the absence of the cover5, until the shoulder 64 engages shoulder 67 in the filter head 4.Shoulder 64 in the sidewall section 7 is provided with a seal member,for example o-ring 68, FIG. 1 to provide for a seal at this location.

Attention is now directed to the serviceable filter cartridge 15,FIG. 1. In general the serviceable filter cartridge 15 includes a second(upper in use) end cap and seal arrangement 20, as indicated previously.The end cap and seal arrangement 20, for the particular embodimentdepicted, are mounted on an end (in use upper end 70) of the primaryfilter cartridge 17. The end cap and seal arrangement 20 includes an endcap portion 71 which, for example, can be a molded member secured (i.e.,potted) to the primary filter cartridge 17. The end cap portion 71includes a central aperture 72, for passage therethrough of liquid (fromregion 35) to be directed in the direction of arrow 40 to circulationloop outlet 31. The end cap portion 71 includes, mounted with a portionin extension over central aperture 72, a projection 72 a, which in thisinstance is a yoke. The projection 72 a is configured to project in anopposite direction (from end cap portion 71), from primary cartridgemedia 17 a. The projection 72 a is configured to be engaged byprojection 62 in cover 5, in use. The projection 72 a would have,typically, a central aperture 72 b, to receive a portion of projection62.

For the arrangement shown, the aperture 72 b is defined by a step, tolimit the extent to which the projection 62 can enter aperture 72.

The end cap 70 also includes a mounting ring 73 and a seal 74. In thisinstance the seal 74 comprises o-ring 75. Although alternatives arepossible, for the particular embodiment shown in FIG. 1, the mountingring 73 is directed outwardly from a remainder of the end cap 71 and ispositioned to secure the seal 74 to define a seal plane that is notorthogonal (or non-orthogonal) to a central axis 78 of the primaryfilter cartridge 17 (or assembly 1). The term “seal plane” as used inthis context, it is meant to refer to a plane in which the materialwhich forms the seal, rests. For example a plane defined by an o-ring 75is shown at 75 a. That is, the plane 75 a in which the o-ring sits, willbe referred to as the seal plane in this context. The term “seal plane”is not meant to refer to the direction of the seal (radially outwardly,radially inwardly or axially). The term is also not meant to refer tothe surface of engagement defined between the seal and the housing. Theterm “seal plane” is merely meant to refer to a plane 75 a defined bythe seal member, for example o-ring 75, which creates the seal. The term“non-orthogonal” and variants thereof, in this context is merely meantto refer to a seal plane that does not extend at an angle A of 90° tothe axis 78. It may alternatively be said that the seal plane 75 aextends at an oblique angle to the axis 78.

In the embodiment of FIG. 1, as a result of the non-orthogonal oroblique angle, the mounting ring 73 divides the internal volume 4 a ofthe filter head 4 into an inlet volume 79 and an outlet volume 80,separated by the o-ring 75. The positioning of the mounting ring 73 (todefine a seal plane non-orthogonal to the central axis 78) allows for aconstruction in which the inlet arrangement 30 and outlet arrangement 31can be positioned generally oppositely to one another in the filter head4 while not needing to be spaced apart, vertically, at all, or at leastnot to a great extent. For the particular embodiment depicted in FIG. 1,a center line 30 b for the inlet aperture arrangement 30 is in a planebelow a center line 31 b for the outlet flow arrangement 31, althoughalternatives are possible.

Typically, the mounting ring 73 will define a seal plane 75 a for seal74 in which the seal 74 defines a circle in a plane at an upper, acute,angle of about 30-60°, inclusive, relative to axis 78, typically about40°-50°, inclusive (for example about 45°). The term “upper” in thiscontext, is meant to refer to an angle between the seal plane and thecentral axis 78, above the seal plane 75. The term “acute” in thiscontext, is meant to refer to the smallest or less than 90° projectionangle between the plane 75 and the axis 78, of the two upper angles. InFIG. 1, the oblique (upper, acute) angle is indicated generally at “A.”

The end cap 71, including the mounting ring 73, can be molded from avariety of moldable plastic materials, for example a polyamide (PA). Aglass filled polyamide (15-30% glass filled by wt.) would, for example,be useable. Of course analogously functioning structure could befabricated from metal components.

Still referring to FIG. 1, it is noted that end cap 71 further includesa shield projection 71 a thereon. The seal projection 71 a projectsdownwardly along an outside 17 b of the media 17 a generally a length ofextension far enough to extend to a point 71 b at or below a lower mostextent of inlet arrangement 30 and outlet arrangement 31. Althoughalternatives are possible, this will accommodate the seal support ormounting ring 73. It also will inhibit fluid entering inlet arrangement30 from directly impinging upon the media 17 a at this location. For atypical cartridge 15, wall or shield projection 71 a will extend adistance, along outer surface 17 b of the media 17, a distance of atleast 15 mm., typically about 25 to 40 mm.

For the particular arrangement shown in FIG. 1, filter media 17 a of theprimary filter cartridge section 17 is secured to, and in operableassembly and orientation depends from, the end cap 71. A variety ofconstructions can be used for the media 17 a of the primary filtercartridge section 17. It is anticipated that for a typical liquid filteroperations, a pleated media 84 configured in a generally cylindricalshape around an open center volume, will be used and preferred. Themedia may be selected from many of a variety of types of media, nowknown or later developed, for liquid filter applications. Typically themedia will comprise a non-woven fibrous material, for example cellulosefibers, synthetic fibers, glass fibers or a mixture thereof. Suchmaterials are widely known for use in liquid filtering. Typical pleatsizes would be about 6-15 mm., although variations are possible.

A central support or inner support 85 may be positioned along an inside17 c of the pleated media 17, for support. A perforated metal liner, orexpanded metal liner, can be used, for the inner support 85. If a metalinner liner is used, the inner liner may, as an example, comprise aporous coiled metal strip, with inner locking edges. If a metal-free orreduced metal configuration is desired for the serviceable cartridge 15,an extruded, perforated or porous liner can be used.

The media 17 may be contained within a mesh or similar structure, ifdesired. The mesh may comprise a metal wire mesh or a plastic mesh, aspreferred.

It is noted that in some instances it is preferred to manufactureserviceable filter cartridges from reduced metal or metal-freecomponents, so as to facilitate disposal. It is an advantage toarrangements according to the present disclosure, that the replaceableor serviceable part, i.e., the filter cartridge 15, can be manufacturedin a reduced metal or metal-free form. Herein the serviceable filtercartridge 15 will be considered a “reduced metal” component, if itcontains no more than 3%, by wt., metal. It will be consideredmetal-free, if it includes no more than 0.1%, by weight, metal.

In some assemblies it may be desirable to provide the primary filtercartridge 17 with an upstream outer liner, or a liner/valveconstruction, in accord with the descriptions of the PCT Application No.PCT/US03/19112, filed Jun. 18, 2003, entitled “ARRANGEMENT FORCONTAINING FILTER CONTAMINANT; ASSEMBLY; AND METHODS,” identifying JohanFobe, Enrico Greco and Julien Dils as inventors and having a priorityclaim to U.S. Ser. No. 60/390,856 filed Jun. 21, 2002 and published asPCT WO 04/000436 on Dec. 31, 2003; hereinafter “the WO/04/000436publication;” incorporated herein by reference.

At an end opposite end cap 71, the primary filter media 17 is secured toend cap 88. End cap 88 is open, having a central aperture 89. This endcap is shown in greater detail in FIG. 1A. FIG. 1A is an enlargedfragmentary view of a portion of FIG. 1.

Referring to FIG. 1A, end cap 88 includes a seal 90, in this instance aninner seal formed from o-ring 91. The seal 90 is positioned to sealagainst a portion of, or structure in, the housing, in this instance theseal being against inner or center stand pipe 45, since end cap 88 is anopen end cap.

Herein, a seal will be considered “radially directed,” if the sealprovided is directed toward or away from central axis 78. For theparticular embodiment depicted in FIG. 1A, the inner seal 90 is aradially directed seal, or radial seal. The particular seal 90 depictedis an inwardly directed seal, when defined with respect to the sealingforce from end cap 88, to which it is attached. In use, it would sealagainst a structure projecting through an aperture defined by end cap88.

Still referring to FIG. 1A, attention is now directed to the bypassfilter 18. The bypass filter 18 comprises a filter media 94 positionedin extension between opposite end caps 88 and 95. End cap 88, whichforms an upper end cap (when operably installed) for the bypass filter18, comprises a lower end cap (when operably installed) for the primaryfilter media 17 a, for the embodiment shown. Preferably both the primaryfilter cartridge media section 17 a and the bypass filter cartridgesection 18 are non-removably secured to the end cap 88. Herein the term“non-removably secured” in this context, is meant to refer to aconnection that cannot be broken without damage to one of the componentsinvolved (i.e., one of the filters or the end cap itself). Typically thebypass filter cartridge section 18 and the primary filter cartridgemedia section 17 a would be secured to the end cap 88 by being potted inthe material of the end cap 88, or by having end cap 88 molded-in-placeon the media.

End cap 95, a third end cap, is an open end cap, having open centralaperture 96. For a typical bypass arrangement, the media 94 wouldcomprise a plastic or wire screen 93, or similar construction. Generallythe media 94 is not intended for long term filtering flow operation, butonly to ensure the equipment is appropriately protected during a periodin which the primary filter media section 17 has become occluded to anextent that a bypass flow in operation is needed.

In a typical application, the axial length of the media 17 a of theprimary filter media section 17, i.e., the length in the direction ofaxis 78, will be at least 3 times (typically at least 4 times) the axiallength of the bypass filter media section 18.

Referring to FIG. 1A, lower end cap 95 is provided with an optionaloutwardly directed lip 98, positioned such that, when serviceable filtercartridge 15 is drawn upwardly through housing 3, FIG. 1, the lip 98 cancatch sediment in annular volume 33 for removal from assembly 1.

Herein, an outwardly directed structure 98 on an end cap such as end cap95, which is directed to collect contaminant during withdrawal of thefilter cartridge 15 from the housing 3, will sometimes be referred to asa “contaminant collection arrangement” or by similar terminology. Theterminology is not meant to indicate any specific structure, other thanan outward projection configured to capture or collect contaminant. Theparticular arrangement 98 depicted in FIG. 1, is an outwardly directedlip sized to engage an inner surface of the side wall 7 and having noapertures therethrough. Thus, sediment in region 33 is directed abovelip 98, and liquid in region 33 into bypass filter 18, when thecartridge 15 is listed out of housing 4.

Attention is now directed to FIG. 9. In FIG. 9, an alternate filtercartridge 15 x is depicted. The filter cartridge 15 x includescomponents analogous to those previously described for filter cartridge95, and thus, for example, includes primary filter media 17 x, innerliner 85 x, end caps 71 x and 88 x. Round end cap 95 x, not havingoutwardly directed lip structure 98 depicted in FIG. 1A, insteadincludes, as an outwardly directed structure, o-ring 95 y. The o-ring 95y will provide a seal with sidewall 7, FIG. 1, when filter cartridge 15x is installed, and will serve a similar function to outwardly directedstructure 98.

Referring to FIG. 9, it is noted that end cap 88 x comprises acombination of end cap 88 y on media 17 x, and end cap 88 z on media 94x. Of course, if desired, end cap sections 88 y and 88 z can be securedtogether by welding adhesive of the like, to form an integral unit. Ifmade of separate pieces, they sometimes preferably would be securedtogether: to avoid leakage therebetween; and, to ensure that element 15x is installed and removed, as a single serviceable piece, when desired.Of course end cap 88 x could be made as a single molded piece.

Referring again to FIG. 1, from the previous descriptions, it can beseen that during a servicing operation, cover 5 would be removed, andthe serviceable filter cartridge 15 (or 15 x), comprising the primaryfilter cartridge 17 (or 17 x) and the bypass filter 18 (or 18 x), wouldbe removed. A new filter cartridge (typically analogous in configurationto the removed cartridge 15 or 15 x) would then be reinserted. The newfilter cartridge 15 (or 15 x) would be pushed downwardly into housing 3until it seats with seal 90 against center pipe 45. The cover 5 can bethen returned, with center stem 62 pressed against projection 72 a onend cap 71 (or analogously on cartridge 15 x). Rotational orientation ofthe serviceable filter cartridge 15 (or 15 x), for proper positioning ofthe mounting ring 73, can be facilitated by providing a shoulder 73 awithin filter head 4 having a shape also at an oblique (non-orthogonal)angle to the center axis 78, so that the filter cartridge 15 (or 15 x)can only be nested in one radial orientation around the axis 78.Generally, projection tip 62 a on projection 62, FIG. 1, is sized to bereceived within aperture 72 b in projection 72 a, in a rotationallyslidable manner. Thus, cover 5 can be rotated, even though, onceinstalled, filter cartridge 15 (or 15 x) cannot be rotated due to thearrangement between mounting ring 73 and shoulder 73 a.

Proper operation of the bypass filter 18, is controlled by the bypassvalve assembly 25, FIG. 1A. The bypass valve assembly 25 is containedwithin housing 3, and, for the embodiment shown, it is not removed andreplaced during servicing of the filter cartridge 15 (or 15 x). That is,bypass valve assembly 25 is configured and positioned to remain with thehousing 3, during servicing operation.

Still referring to FIG. 1A, the bypass valve assembly 25 comprises avalve member 100, in this instance a tubular valve member 101 slidablypositioned within seat 102. For the example shown, the seat 102comprises a lower portion 103 of center pipe 45, although alternativesare possible. In the example shown, the lower portion 103 has a slightlylarger internal diameter (i.d.) than an upper portion 103 a. The valvemember 100 is slidably positioned to open or close an aperturearrangement 104, in lower portion 103. The bypass valve assembly 25 isprovided with a control biasing member (in this example a helicalspring) 105 positioned under compression between ring 106 (in particularat internal shoulder 106 a, in center pipe 45, in this example at aregion of transition between portions 103 and 103 a, of tube or pipe45), and shoulder 107, on tubular valve 101. If the pressure in region109, in particular operating on shoulder 110 of valve member 100 becomessufficiently large relative to pressure in volume 35, the closing forceof the control spring 105 will be overcome, the valve member 100 willslide in the direction of arrow 111, to open apertures 104 to liquidflow therethrough. This opening of the apertures 104 allows for a bypassflow through media 94, into center pipe 45. From there, of course, theliquid flow can either flow through region 35 and out to outletarrangement 31 in the filter head 4, FIG. 1, or into the tank reservoirvia flow path 49, FIG. 1, and upon exit through reservoir inlet/outlet42. Typically, the bypass valve assembly 25 will be configured to openunder a differential pressure defined by the equipment manufacturer, ofthe system in which the filter assembly 1 is installed.

Referring to FIG. 1A, o-ring 101 a, is positioned around tubular valvemember 101, to provide a seal against region 103.

Further understanding of the bypass valve arrangement can be understoodby reference to FIGS. 1B, 1C and 1D. In these Figs., the componentry isanalogous to those shown in FIGS. 1 and 1A, except for differences indetail. However the basic components and operation are the same, and arenumbered accordingly. It is noted that stem 66, FIGS. 1B-1D, isconfigured for attachment to further subassembly described below, in adifferent manner.

As indicated previously, at end 65 side wall 7 includes, projectingtherefrom, a tube section 66 preferably of smaller diameter orcross-sectional area, then region 7 a. Within region 66, for theembodiment shown, is positioned a stay structure or ring 113, FIG. 1C,mounted in tube 66, to contain the bypass assembly 25 in operableposition. The ring 113 can be mounted, after the bypass valve assembly25 is inserted into lower region 103 of tube 45, in a variety of ways,for example through sonic welding, if ring 113 and the tube 7 are bothmade from appropriate plastic materials; or, by using snap fit.

In general terms, end cap 88, FIG. 1A, between the primary filtercartridge section 17 and the bypass filter cartridge section 18, can beviewed as a first end cap having a seal 90 thereon, engaging thehousing, in this instance center tube 45, to separate the tube 45between an upper section 103 a and a lower section 103. The uppersection 103 a will generally have an imperforate side wall (and an openend 103 b) and the lower section 103 would have apertures 104 therein(and an open end 103 c). End cap 71 can be viewed as a second end cap,positioned at an opposite end of media 17 a of the first end cap 88. Endcap 95 can be viewed as a third end cap, positioned at an opposite endof bypass filter cartridge section 18 from the first end cap 88.

Attention is now directed to structural features attached to an outletend 66 a, of tube 66, FIG. 1. That is, in normal operation, theequipment now characterized will be in operable position below side wallsection 7, during operable assembly, typically submerged within a tankreservoir. With respect to this description, attention is directed toFIG. 3, which is an enlarged, fragmentary, cross-sectional view of aportion of FIG. 1.

In this region of the assembly 1, FIG. 3, attention is first directed tothe flow/pressure regulation valve assembly 47. The flow regulationvalve assembly 47 includes a valve member 151 mounted within a housing152. The housing 152 is secured to lower outlet end 66 a of housing 3.The valve member 151 is positioned (under biasing pressure or control bya biasing member, in this instance helical (coiled) spring 155), into asealing engagement between top 151 a and aperture 156, in circular seat156 a. If the pressure within volume 158 (i.e., the pressuredifferential across aperture 156) exceeds the opening pressure, thevalve 151 will move out of sealing engagement with aperture 156, toallow flow in the direction of arrow 160 into region 161, after whichthe flow can then pass through apertures 162 in valve member 151 intocenter region 163, underneath valve top 151 a and outwardly from theliquid filter assembly 1, through outlet 48 in the direction of arrow49, to the tank (liquid) reservoir. Typically, the flow/pressureregulation valve assembly will be configured to open at a selectedpressure differential within the range of 0.3-0.7 bar, for example 0.5bar.

As indicated previously, the particular liquid filter assembly 1depicted, includes a suction filter arrangement 10. The suction filterarrangement 10 includes media 170, in this instance positioned inextension between opposite end caps 171 and 172, to surround and definea central volume 173. The media 170 would typically comprise acylindrical wire mesh or plastic mesh media, typically pleated,supported by a porous inner liner 174. A variety of alternate mediaarrangements can be used for the media 170, including for examplenon-woven media of cellulose synthetic or glass fibers. Non-pleatedarrangements can also be used. The choice of media would typically bemade for the particular environment of use. However for a typicalenvironment involving hydraulic fluids, the intake filter assembly wouldtypically use a wire mesh or plastic mesh screen.

The end caps 171, 172 can be molded from a polymeric material, such as apolyamide, typically a glass-filled (for example 15-30% glass filled, bywt.) polyamide. When fashioned this way, they can be convenientlysecured, during molding, to the media 170. Alternatively, end caps 171,172 can be fabricated metal parts, secured by potting with adhesive.

End cap 171 is shown secured to extension 66, for example by rivets 66 xalthough alternate means of securement (such as adhesive or sonic weld)can be used. An additional seal between end cap 171 and tube 66, ifdesired, could be provided by a gasket at region or joint 176. (In FIGS.3A-3B discussed below, an alternate way of connecting parts that performthese functions is shown.)

For typical preferred arrangements according to the present disclosure,the media 170, again, is configured in a cylindrical form, around acentral longitudinal axis 175 b. The typical “directionally biased valvearrangement” which utilizes cut valves or flaps, is configured so thatthe flaps open for movement toward the central axis 175 b. This isdescribed in greater detail below.

Referring again to FIG. 3, preferably, the outside dimensions for thesuction filter arrangement 10 are such that the suction filterarrangement 10 can be pushed through aperture 63, FIG. 1, along withside wall 7, during assembly. That is, the suction filter arrangement 10can be mounted on the side wall 7 prior to the side wall 7 beinginstalled in the filter head 4, FIG. 1.

Returning to FIG. 3, suction filter arrangement 10 includes, positionedtherein, a directionally biased valve arrangement 54. Herein the term“directionally biased valve arrangement” is meant to refer to a valvearrangement that readily allows liquid flow therethrough in onedirection, but generally is configured to inhibit or resist liquid flowtherethrough in an opposite direction. A variety of mechanisms can beused to provide for such a directionally biased valve arrangement. Theparticular one depicted, is a non-helically coiled spring arrangement(or non-helical spring arrangement) that utilizes one or more cut valves(typically flaps) that can open in one direction, but generally not inan opposite direction as described.

The term “non-helically coiled spring arrangement,” and variantsthereof, in this context, is meant to refer to directionally biasedvalve arrangement that does not utilize a helically coiled spring tomaintain closure of the valves. The term “flaps” in this context, aswill be apparent from the more detailed discussion below, referencesvalve members that can swing or pivot open and closed, as describedbelow.

The term “directionally biased valve arrangement,” and variants thereof,in this context, refers to an arrangement other than a simple perforatedliner, which is (equally open to flow in either direction. A particularconfiguration is discussed below.

For typical preferred arrangements according to the present disclosure,the media 170, again, is configured in a cylindrical form, around acentral longitudinal axis 175 b. The typical “directionally biased valvearrangement,” which utilizes cut valves or flaps, is configured so thatthe flaps open for movement toward the central axis 175 b. This isdescribed in greater detail below.

Although alternatives are possible, for the particular arrangementdepicted, the directionally biased, non-helically coiled spring, valvearrangement 54 is positioned within central volume 173, is surrounded bymedia 170, and is configured so that flow from media 170 into tube 66,is relatively easy, by comparison to reverse flow, i.e., flow frominside tube 66 through the valve arrangement 54 directly to media 170.

The particular directionally biased valve assembly 54 shown, comprises:(a) ring-shaped valve member 175, defining an internal volume 175 aaround central axis 175 b (corresponding in this instance to axis 78)and including at least one and typically a plurality of cut valves 176therein; and, (b) an outer support 178 having at least one and typicallya plurality of apertures 179 therein. The ring-shaped valve member 175is positioned within the outer support 178, for proper operation. Thecut valves 176 are preferably configured so that they can be biased toopen by pivoting (in this instance the flaps 176 a can pivot open towardcenter axis 78). Preferred cut valves 176 have a generally u-shapedorientation, such as that shown. The particular cut valves 176 depictedhave a “boxed” u-shape orientation, with each of the centers of theu-shaped cuts, pointed in the same direction around axis 78. By “boxed”in this context, it is meant that the cut valve 176 is formed from threestraight cuts, and it is not meant that any particular angles betweenside cuts 176 b and the center cut 176 c are required. A variety ofalternate cut valve shapes can be used, including, for example, curvedu-shapes; i.e., u-shapes with curved center cuts. For the embodimentshown, the u-shaped flaps point around the axis 175 b (the term “point”is meant to refer to the direction each u-shape is directed, if it isviewed as an arrow, with edge 176 c being the lead edge).

A variety of materials can be used for the ring member 175, a particularpreferred material would be spring steel, for example spring steelhaving a thickness of about 0.05 to 0.2 mm., typically about 0.1 mm. Asingle piece of spring steel can be used for the ring member 173, thespring steel piece having been curved in a desired shape to bepositioned within the outer support 178.

In general, the outer support 178 has a sufficient internal diameter, tocontain the ring member 175 securely therein. The apertures in the outersupport 178 are preferably positioned and sized so as to be covered bythe cut valves 176 in operation. A mechanical index can be providedbetween the ring member 175 and outer support 178, for example byproviding a rib on the outer support 178 which projects toward centerline 78, and by also providing the ring with a gap to engage the rib.Such an indexing arrangement between an outer support and a valve sheethaving cut valves therein, is described for example in PCT PublicationWO 04/000436, for a different type of assembly.

It is noted that, as indicated above, some of the features of thedirectionally biased valve arrangement 54 may be analogous to featuresfor a valve arrangement described in the WO 04/000436 PCT publication.However, when arranged as shown in FIG. 3, the operational purpose tothe valve arrangement 54 is substantially different from those describedin the WO 04/000436 PCT publication. In particular, the valvearrangements described in the WO 04/000436 PCT publication, aregenerally positioned at an upstream side of media in a main filterelement, for example around the outside of a cylindrical media, tocontain contaminant against the media in use and during servicing. Thevalve arrangement 54 described in the current application, is positionedin a part that is not normally changed out during servicing. Also,although alternatives are possible, it is downstream of the media 170with which it is associated. The purpose of the valve arrangement 54 isto allow liquid flow in one direction, and to inhibit reverse liquidflow. The valve arrangement 54 when positioned as shown has nocontaminant containment purpose. In fact in the example shown it islocated in a filtered liquid volume, although alternatives are possible.

Even if the valve arrangement 54 were positioned around the outside ofmedia 170, its operation would still be primarily different from that ifthe arrangements of WO 04/000436 PCT publication, since its operation inconnection with the principles described herein, would be to manage aportion of filter flow, as opposed to flow with respect to a main orprimary serviceable filter cartridge.

Referring to FIG. 3, in general, flow in a direction opposite to arrows50, i.e., from region 173 through the media 170, is inhibited by the cutvalves 176, since they cannot readily be biased open by outwardmovement, i.e., away from center line 78, due to the presence of theouter support 178. As a result, the combination of the ring member 175,with the cut valves therein, and the outer support 178, provides for adirectionally biased valve arrangement; i.e., it provides for lessresistance to liquid flow in the direction from media 170 to volume 35,then in the opposite direction, without use of a helically coiledspring.

To facilitate a one-way operation for the flaps 176 a, outer support 178is preferably configured with a structural portion overlapped by theflaps 176 a.

Still referring to FIG. 3, it is noted that for the particular assembly10 depicted, the upper end cap 171 is integral with componentry whichdefines the outer support 178. Of course alternate configurations arepossible. One such arrangement is shown in FIG. 4.

Referring to FIG. 4, like numerals are used to indicate analogouscomponentry. The basic difference between the assembly of FIG. 4 and theassembly of FIG. 3 relates to selected structural shapes and joints. Inparticular the media 170 for the suction valve arrangement 200 is shownextending between end cap 201 and end cap 202. End cap 202 is integralwith a side wall 203 in which the flow/pressure regulation valveassembly 47 and directionally biased valve assembly 54 are positioned.These components 47, 54 may be as generally described above. Disk orring 210 provides both: for a sealing seat at aperture 211, for theflow/pressure regulation valve assembly 47; and, also, as a base for thedirectionally based valve assembly 54. Disc 210 can be inserted throughend 212, after the flow/pressure regulation valve assembly 47 has beeninserted.

From a comparison of FIGS. 3 and 4, a variety of possible componentryconfigurations and assemblies will be understood. One particular set isillustrated in FIG. 5.

In FIG. 5, components of a pressure regulation valve arrangement andsuction valve assembly (usable in arrangements as characterized herein)are shown. Referring to FIG. 5, a ring member is depicted at 300. Thering member 300 may be used in accord with the description above, forring shaped valve member 175.

A flow/pressure regulation valve member is depicted at 310. This valvemember may be used generally and analogously to the valve member 151,FIG. 3. In FIG. 5, a control spring 320 for use with the flow/pressureregulation valve member 310, in accord with spring 155, FIG. 3 is shown.

Also depicted in FIG. 5, is a valve frame piece or structural piece 330.The ring member 300 can be inserted into structural piece 330 throughupper end 331.

At 332, structural piece 331 is shown with an aperture arrangementtherein, through which flow can go, controlled by cut valves 333, inthis case flap valves, in ring member 300.

The spring 320 and then the valve head 310 can be inserted intostructural piece 330 through end 331, i.e., the end opposite end 340. Atend 340, internally, a stop arrangement would be provided, to preventthe spring from passing completely through end 340.

In typical assembly, spring 320 would first be dropped through end 331,with valve head member 310 next. Disc 341 would then be positioned inplace above the valve member 310. Ring 300 would then be inserted. Theresulting assembly could then be mounted on a tube such as tube 66, FIG.3, with an end 66 a of the tube projecting into the opening 331, to abutring 300 and secure the flow/pressure regulation valve assembly 47 inplace.

Of course alternate specific combinations to the components to form thesuction filter arrangement 10 and the sidewall arrangement 7, can beused. An example is shown in FIGS. 3A and 3B.

Referring to FIG. 3A, the sidewall 7, as depicted in FIG. 1B, includesan end projection 66 having an o-ring groove 66 j therein, for receiptof o-ring 66 k. Suction filter assembly 10 is mounted on projection 66with o-ring 66 k therethrough, projection 10 x extending aroundprojection 66, during assembly. This is shown in FIG. 3B, in theassembled form. It is noted that a threaded connection at this location,can be used, as shown in FIG. 3B at 10 y. It is also noted thatvariations in the specifics of the suction filter arrangement 10 and theflow/regulation control assembly 47 are also possible. In connectionwith this, attention is directed to FIGS. 6-8.

Referring to FIG. 6, subassembly 250 is depicted comprising suctionfilter 260 mounted on adapter 261 and, surrounding flow regulationassembly 265.

Adapter 261 includes threads 261 x thereon, for attachment to projection66, FIGS. 3A and 3B.

Suction filter assembly 260 comprises opposite end cap 268, 269 with:suction filter media 270 extending therebetween. Internally of media 270is positioned a non-helically spring directionally biased valve member271, comprising two vertically spaced rows of u-shaped flap valves 272.Ring 271 is positioned inside of support 273. Support 273 is positionedinside of liner 274. Liner 274 is a media inner liner, in this instancecomprising a coiled strip of metal, with edge roll seams.

End cap 269 is configured to include flow regulation valve assembly 265therein, comprising valve head 280 positioned in valve stem 281. Aspring would be positioned internally of valve stem 281 for control ofvalve member 280.

Functional operation of assembly 250 would be analogous to suctionfilter 10 described previously.

In FIG. 7, assembly 250 is shown in exploded view, so that selectedparts can be viewed.

In FIG. 8, end cap 269 with valve assembly 265 thereon is depicted ingreater detail. It can be seen that valve piece 281 is positioned withinstem 282, with apertures 290 allowing for flow. In this case, valve 281is a tubular member, slidably positioned between spring 291 and top 292.

Attention is now directed to FIG. 2, with respect to general operationof components previously described. In FIG. 2, a schematic diagram isprovided, for an understanding of the general operation. Referring toFIG. 2, a liquid tank reservoir is indicated generally at 400. At 401,an inlet line to a filter arrangement for example according to filter 1,FIG. 1, as shown. Line 401 would, for example, correspond to inlet line30 a. Line 402 generally depicts an outlet flow into a circulationsystem, of filtered liquid. Line 402 would generally correspond tooutlet flow path 41, FIG. 1.

At 405, the primary filter arrangement having filter media is shown.This filter media would generally correspond to the filter media at 17,FIG. 1. In normal flow, then, liquid would enter from flow path 401, gothrough filter 405, and then, if needed, would exit through exit line402.

Regulation flow to allow the liquid to go into the reservoir, would becontrolled by flow regulation valve 410, FIG. 2. Regulation valve 410could, for example, correspond to flow/pressure regulation valveassembly 47, FIG. 1. Thus, if the pressure in line 411 reaches anadequate limit, valve 410 would open up, allowing flow from line 401 togo directly into tank reservoir 400.

Still referring to FIG. 2, the bypass filter is indicated generally at420. Should the pressure differential across filter 405, i.e., betweenregions 421 and 411 (measurable by differential pressure gauge 422)exceed an appropriately defined limit, bypass valve 421 will open,allowing flow through bypass filter 420 into region 411, from which itcan be directed either into circulation via outlet line 402, or into thetank reservoir 400 through flow/pressure regulation valve 410. Thefilter 420 can generally correspond to bypass filter 18 and the bypassvalve 421 can generally correspond to bypass valve 25, FIG. 1.

A suction valve assembly is generally indicated at 440, comprisingsuction filter 441 and directionally biased valve arrangement 442.Filter 441 can (if desired) generally correspond to filter 51, FIG. 3;and, directionally biased valve arrangement 442 can (if desired)generally comprise arrangement 54, FIG. 1, or the other variationsdescribed. Of course valve 442 could be positioned at region 442 a ifdesired.

It will be understood that should there be a need for a liquid from thetank reservoir 400 into region 411, the liquid can be drawn throughfilter 441 and through directionally biased valve arrangement 442, intoregion 411. However, being directionally biased, flow from region 411 isinhibited from going through valve arrangement 442.

From the above principles, it will be apparent that the techniques andprinciples described herein can be applied in constructions of a varietyof configurations, sizes and materials. It is an advantage that thedescribed principles, however, can be applied in a relatively compactunit. The following ranges of dimensions are not intended to belimiting, but rather as an indication of how the principles can beapplied, in preferred, compact, orientations. The dimensions refer todimension lines found in FIG. 1. In particular, dimension G, FIG. 1,would be about 65-85 mm., typically 70-75 mm.; dimension H wouldtypically be 25-45 mm., for example about 32 mm.; dimension I wouldtypically be about 200-250 mm., for example about 227 mm.; dimension Jwould typically be about 60-80 mm., for example about 70 mm.; anddimension K would typically be about 25-50 mm., typically about 35 mm.In a particular example constructed in accord with FIG. 1, useabledimensions would be as follows: dimension G, 74 mm.; dimension H, 32.3mm.; dimension I, 227 mm.; dimension J, 70 mm.; and dimension K, 35.3mm.

Based on the above descriptions, methods of assembly will be apparent.The methods of assembly generally comprise inserting the variouscomponent parts, where indicated, into the assemblies. For example oneset of steps of a method of assembly would include inserting componentsof a bypass valve arrangement through a lower end of a housing and intoan interior of a stand pipe, as shown. In general, in the arrangementshown in FIG. 1, the steps would comprise inserting a ring 106 a,inserting a spring 105 and then inserting a valve slide 101, followed byclosure with a cover 113.

Another method of assembly would include assembling a suction filterarrangement 10 including both a first non-helical coiled spring,directionally biased valve arrangement and a flow/pressure regulationvalve arrangement, as shown. One method of assembly was described, inconnection with FIG. 5. The particular order of insertion of componentrycan be directed, by controlling the shape and size of variouscomponents.

Also according to the present disclosure, preferred serviceable filtercartridge arrangement is described. The filter cartridge arrangementincludes a first primary filter cartridge section and a second bypassfilter cartridge section. The two are joined at a first end cap. Thefirst end cap also preferably includes a seal therein for sealing to aframe piece, such as stand pipe during insertion. For the example shown,FIG. 1, the seal is on an inside of the first end cap. A second end capis provided at an opposite end of the primary filter cartridge section,from the first end cap. For the examples shown, FIGS. 1 and 9, thesecond end cap preferably includes a seal mount thereon defining a sealplane extending at a selected angle non-orthogonal to a central axis ofthe primary filter cartridge section, although alternatives arepossible. Preferably the selected, acute, non-orthogonal angle is withinthe range of 30°-60°, inclusive. Such an arrangement can easily beaccommodated, by molded structural portions of the end cap defining anouter o-ring seal group.

Although alternatives are possible, the filter cartridge preferablyincludes an upper projection (or yoke) on an opposite side of the secondend cap, from the side from which the media of the primary filtercartridge extends. This projection preferably allows for flow through anopening in the second end cap, while at the same time providing a stopto insertion of a projection from a top of the housing.

The second end cap also preferably includes a shield arrangementcircumscribing a portion of the filter media of the primary filtercartridge section. The shield section generally extends along an outsideof the primary filter cartridge section a length equal to or greaterthan a diameter of an inlet port or outlet port in a correspondinghousing, during use.

In some instances, the bypass filter arrangement can include a third endcap having a contaminant collection projection extending outwardlytherefrom.

A method of servicing is provided, which preferably involves steps ofopening a top cover of a housing, removing a filter cartridge 15according to the general descriptions herein, and replacing it with anew, or refurbished, filter cartridge arrangement.

Methods of use of the assembly were described, in connection with FIG.2. They generally provide for allowing for flow into and out of areservoir, under the control provided, as well as a circulating flow,with filtering as described.

As described above, the principles of construction and operation withrespect to the arrangement described in connection with FIGS. 1-9, canbe applied in a variety of arrangements. They are particularlyconfigured for use in arrangements with an expected flow into the inletarrangement 130 and out of the outlet arrangement 131 on the order of upto about 120 liters per minute, for hydraulic systems.

In association with FIGS. 10-26 below, an arrangement that utilizes manyof the same principles described is provided, for systems in which ahigher flow rate, as described, is expected.

II. A Second Embodiment; FIGS. 10-29

The principles described generally above, can be applied in arrangementshaving alternate specific features, and configured for still furtherapplications. In FIGS. 10-29 such an arrangement is depicted, forapplication in hydraulic systems with expected flow rates, for example,of up to about 250 liters per minute. Of course the principles could beapplied, to construct arrangements to allow for alternate flow rates, ifdesired.

As will be apparent from the following descriptions, many of thefeatures depicted have analogous functions and operate analogously tofeatures described previously, in connection with FIGS. 1-9.

The reference numeral 601 FIG. 10 generally indicates a liquid filterarrangement or assembly according to this aspect of the presentdisclosure. The liquid filter assembly 601 includes a housing 603comprising a filter head 604 having a body 604 a and a removable top orcover 605; and, a side wall 607, which in use depends from filter head604. In general, the housing 603 defines an internal volume 608, FIGS.11 and 12, in which: selected internal componentry as defined iscontained; and, certain filtering and flow operations occur. The liquidfilter assembly 601 further includes a suction filter assembly 610.

The liquid filter assembly 601 includes, operably positioned therein, aserviceable filter cartridge arrangement 615, FIGS. 11, 12, 19 and 20.For the particular, preferred, liquid filter arrangement 601 shown, theserviceable filter cartridge 615, FIGS. 19 and 20, optionally includestwo filter sections or components namely: a primary filter cartridge orcartridge section 617; and, a bypass filter cartridge or cartridgesection 618. The primary filter cartridge section 617 and bypass filtercartridge section 618 can be secured to one another, and be removed andserviced as an integral unit.

Of course, the primary filter cartridge or cartridge section 617 is notrequired to be integrally (non-separably) attached to the bypass filtercartridge or cartridge section 618. However, the arrangement depicted,in which the two are permanently secured to one another (or areintegral), is convenient and typical.

The preferred serviceable filter cartridge assembly 615, FIG. 20,further includes, as described below, an end cap and seal arrangement620, which provides for a preferred mounting and sealing of theserviceable filter cartridge arrangement 615, within the liquid filterarrangement 601.

The preferred liquid filter assembly 601 depicted includes a bypassvalve assembly 625, FIGS. 11 and 12.

Referring to FIGS. 10 and 11, typical operation of the variouscomponents defined, will be generally in accord with the descriptionabove, for assembly 1, FIG. 1. The filter head 604 generally includes abody 604 a having an inlet or inlet arrangement 630 and an outlet oroutlet arrangement 631. Again, the liquid flow inlet arrangement 630will sometimes be referred to as a circulation loop liquid flow inletarrangement, since it is an inlet to the filter head 604 of liquid froma circulation loop in which the liquid circulates to perform itsfunction. Similarly the outlet arrangement 631 will sometimes bereferred to as a circulation loop liquid flow outlet arrangement, sinceit is an outlet for filtered liquid, from the filter head 604 and thusthe assembly 601, for the liquid to be directed into a circulation loopto perform its function. As for FIG. 1, in both instances, the terms aremeant to distinguish an inlet/outlet arrangement, discussed below,referenced as the reservoir inlet/outlet, which provides for liquid flowfrom the assembly 1 directly into a liquid reservoir.

Referring to FIG. 16, for the particular assembly shown, the filter head604 includes, for the inlet arrangement 630, two inlets 630 x and 630 y;and for the outlet arrangement 631, two outlets 631 x and 631 y. Thisallows assembly 601 to be operated with two circulation loops, forfilter liquid. The assembly 601 is to be used with only a singlecirculation loop, since one of inlet 630 x, 630 y and one of outlet 631x and 631 y can optionally be closed or capped.

Referring to FIG. 11, liquid to be filtered is directed into inletarrangement 630. The unfiltered liquid then flows into annularunfiltered liquid volume 633, around the serviceable filter cartridgeassembly 615. In general, volume 633 is an “unfiltered liquid volume,”since the liquid received therein, will generally be received directlyfrom a circulation loop, and will be unfiltered and will requirefiltering.

In normal operation, from the unfiltered liquid volume 633, the liquidis passed through the primary filter cartridge 617 to its interior 635.(This would be a filtering flow.) From the central volume 635 the liquidcan pass out of the filter cartridge 615 in a direction of arrow 640 tooutlet arrangement 631, and outwardly from the assembly 601. (The flowfrom volume 635 through outlet arrangement 631 is a non-filtering flow.)

To address the event that liquid flow demands in the circulation loopdownstream of the assembly 601, i.e., in the direction of arrow 640, arenot sufficiently great to require all filtered liquid entering region635 to be directed into the circulation loop by passage (afterfiltering) through outlet arrangement 631, as with arrangement 1, FIG.1, an alternate flow direction is provided. In particular, flow fromcentral volume 635 can be directed outwardly from the housing side wall603, and eventually outwardly from the assembly 601 and into a tankreservoir, by passage through reservoir outlet/inlet (or inlet/outlet)642.

Although alternatives are possible, it is noted that assembly 601, FIG.11, does not include a central standpipe analogous to standpipe 45,positioned in and secured to sidewall 607. A structure 900 whichreplaces standpipe 45, with respect to certain functions, is discussedin more detail below.

As with arrangement 1, FIG. 1, in a typical operation, a flow pathindicated by arrow 649, from region 635, would be a liquid flow exitfrom assembly 601 into a tank reservoir, not shown in FIG. 11. Intypical use, although alternatives are possible, the liquid filterassembly 601 would be an in-tank assembly in accord with the principlesdescribed herein and would be mounted on a reservoir tank with suctionfilter assembly 610 submerged in the reservoir.

With the particular, preferred, liquid filter assembly 601 depicted,flow/pressure regulation valve arrangement 647 is convenientlypositioned on the suction filter assembly 610, as described in detailbelow, although alternatives are possible.

As with arrangement 1, FIG. 1, from the above descriptions, it can alsobe expected that in some circumstances, for assembly 601, there may be aflow demand increase downstream of the liquid filter arrangement 601,relative to the liquid volume and flow going into inlet arrangement 630.When this occurs, liquid will be drawn from the tank reservoir in thedirections of arrows 650, FIG. 11, eventually into central volume 635.Such a flow will generally be through suction filter 651, in suctionfilter arrangement 610, and is a filtering flow. A directionally biasedflow arrangement 652, preferably as described in detail below, isprovided in the suction flow path. The directionally biased flowarrangement 652 allows for entrance of liquid into region 635, butinhibits liquid flow in an opposite direction, so as not to override ordisable a proper bypass operation of flow/pressure regulation valvearrangement 647. The preferred directionally biased flow arrangement 652depicted, is a non-helical spring valve arrangement 652 a, discussedbelow. It is noted that for the embodiment depicted in FIG. 11, thenon-helical spring valve arrangement 652 surrounds the filter 651,although alternatives are possible.

To protect the equipment in the circulation loop, in circumstances inwhich the primary filter cartridge section 617 becomes occluded to anundesirable level, a bypass filter arrangement 655, FIG. 11, isprovided. The bypass filter arrangement 655 includes bypass filter 618and bypass control valve arrangement 625. In general, should thepressure differential across media 617 a in primary filter cartridge 617become sufficiently high, the bypass control valve 625 is configured toopen, to allow liquid flow through bypass filter 618 and into centralvolume 635, as a filtering flow but without passage through filter media617 a in primary filter cartridge 617. As with assembly 1, FIG. 1, thisflow can then proceed, in the direction of arrow 640, FIG. 11, throughoutlet arrangement 631, or into the reservoir by passage throughreservoir inlet/outlet 642 and from assembly 601 via the pathway ofarrow 649.

The bypass filter arrangement 655 is discussed further below, inconnection with FIG. 12.

For a typical liquid filter assembly 601, filter head 604 will be a castmember, for example made from cast aluminum or other material. Cover 605is secured by bolts 606, FIG. 11, to the filter head 604, to closeservice aperture 605 a, with a seal provided by o-ring 660. The cover605 includes handle 661 and extensions 661 a, for bolts 606. An optionalbleed valve assembly can be located at 663 a. In FIGS. 14 and 15, cover605 is shown in greater detail, but without bolts 606.

The cover 605 includes positioned internally and centrally, a stem 662,configured to project into a central volume 604 b of filter head 604.The filter cartridge 615 is sealed to stem 662 by seal 620 a on stem620. In particular, stem 620, on cartridge 615, projects inside of stem662, on cover 605.

In use, spring 663 is positioned inside the stem 662, FIG. 11, to ensurethat the serviceable filter cartridge 615 is retained in extension intothe housing 603, at an appropriate position and to ensure that thecartridge 615 cannot be moved out of its operational (sealed) position,unless cover 605 is removed. For the arrangement 601 shown, spring 663is conically shaped, with narrow end 662 b and wide end 662 c.

Analogously to arrangement 1, FIG. 1, the sidewall portion 607 of theliquid filter assembly 601 depicted, FIG. 10, is separable from thefilter head 604. In particular, the body 604 a of filter head 604, FIG.11, includes an aperture 664 therein positioned on opposite side ordirection of the filter head body 604 a from the service aperture 605 aand cover 605. The sidewall section 607, projects through, and outwardlyfrom (in use downwardly from), the aperture 663.

The sidewall section 607, is depicted in FIGS. 17 and 18. In FIG. 17,the sidewall section 607 is shown with wire handle 617 a, which can berotated down. In FIG. 18, the sidewall section 607 is shown without thehandle. The sidewall section 607 has shoulder 664 (at an upper end inuse) and an opposite (in use bottom) end 665. The side wall 607 is sizedsuch that, during assembly, when the top 605 is removed from body 604 a,FIG. 11, the side wall 607 can be lowered into the housing 603 throughthe opening 605 a provided by the absence of the cover 605, until theshoulder 664 engages shoulder 667 in the filter head 604. Shoulder 664,FIG. 11, is provided with a seal member 668, to provide for a seal atthis location.

Attention is now directed to the serviceable filter cartridge 615, FIGS.19 and 20. In general the serviceable filter cartridge 615 includes thesecond (upper in use) end cap and seal arrangement 620, referencedabove. The end cap and seal arrangement 620, for the particularembodiment depicted, are mounted on an end (in use upper end 670) of theprimary filter cartridge 617. The end cap and seal arrangement 620include an end cap portion 671 which, for example, can be a moldedmember secured (i.e., potted) to the primary filter cartridge 617. Theend cap portion 671 includes a central aperture 672, for passagetherethrough of liquid (from region 635) to be directed in the directionof arrow 640 to circulation loop outlet arrangement 631. The end capportion 671 includes axial projection 672 a. The projection 672 a istubular with an outer surface and projects in an opposite direction(from end cap portion 671), from primary cartridge media 617 a. Theprojection 672 a is configured to project into projection 662, FIG. 11,with sealing by o-ring 620 a, as previously mentioned. The o-ring orseal, then, is mounted on an outside surface of, and surrounds,projection 672 a.

The end cap 671 can be molded from a variety of moldable plasticmaterials, for example a polyamide (PA). As an example, a glass filledpolyamide (15-30% glass filled by wt.) is useable. It can also be formedas a metal piece.

Referring to FIG. 20, it is noted that end cap 671 includes a shieldprojection 671 a thereon. The shield projection 671 a projectsdownwardly along an outside 617 b of media 617 a in cartridge 617generally a length of extension far enough to extend to a point at orbelow a lower most extent of inlet arrangement 630 and outletarrangement 631. This will inhibit fluid entering inlet arrangement 630from directly impinging upon the media 617 a at this location.

A central support or inner support 685 may be positioned along an inside617 c of the pleated media 617, for support. A perforated metal liner,or expanded metal liner, can be used, for the inner support 685. If ametal-free or reduced metal configuration is desired for the serviceablecartridge 615, an extruded, perforated or porous liner can be used. InFIG. 20, a preferred coiled strip with an edge coupling used for liner685.

The media may be contained within a mesh or similar structure, ifdesired. The mesh may comprise a metal wire mesh or a plastic mesh, aspreferred.

In some assemblies it may be desirable to provide the primary filtercartridge 617 with an upstream outer liner, or a liner/valveconstruction, in accord with the descriptions of the PCT Application No.PCT/US03/19112, filed Jun. 18, 2003, entitled “ARRANGEMENT FORCONTAINING FILTER CONTAMINANT; ASSEMBLY; AND METHODS,” identifying JohanFobe, Enrico Greco and Julien Dils as inventors and having a priorityclaim to U.S. Ser. No. 60/390,856 filed Jun. 21, 2002 and published asPCT WO 04/000436 on Dec. 31, 2003; hereinafter “the WO/04/000436publication;” incorporated herein by reference.

Referring still to FIG. 20, at an end opposite end cap 671, the primaryfilter media 617 is secured to end cap 688. End cap 688 is open, havinga central aperture 689. The end cap 688 includes tubular axialprojection 688 a projecting axially away from media 617 a, with an outersurface having a seal 698 b (in this instance an o-ring) extendingperipherally therearound.

For the particular embodiment depicted in FIG. 20, the inner seal 688 bis a radially directed seal, or radial seal. The particular seal 688 bdepicted is an outwardly directed seal, when defined with respect to thesealing force from end cap 688, to which it is attached. Seal 688 bprovides a seal to another component, discussed below. Seal 688 b issurrounded by, and spaced from, the bypass filter media, as discussedbelow.

Referring to FIG. 20, attention is now directed to the bypass filter618. The bypass filter 618 comprises a filter media 694 positioned inextension between opposite end caps 688 and 695. End cap 688, whichforms an upper end cap (when operably installed) for the bypass filter618, comprises a lower end cap (when operably installed) for the primaryfilter media 617 a, for the embodiment shown. Preferably both theprimary filter cartridge media section 617 a and the bypass filtercartridge section 618 are non-removably secured to the end cap 688.Typically the bypass filter cartridge section 618 and the primary filtercartridge media section 617 a would be secured to the end cap 688 bybeing potted in the material of the end cap 688.

End cap 695 is an open end cap, having open central aperture 696. For atypical bypass arrangement, the media 694 would comprise a plastic orwire screen 693, or similar construction. Generally the media 694 is notintended for long term filtering flow operation, but only to ensure theequipment is appropriately protected during a period in which theprimary filter media section 617 has become occluded to an extent that abypass flow in operation is needed.

Still referring to FIG. 20, it is noted that a portion of media 694 ispositioned to surround projection 688 a, with seal 688 b, spacedtherefrom by gap 697. Thus, projection 688 a extends into an openinterior of the bypass filter arrangement 618. Gap 697 is a receivinggap or channel, for a tubular part of a structural member as describedbelow.

As with arrangement 1, FIG. 1, in a typical application, the axiallength of the media 617 a of the primary filter media section 617, i.e.,the length in the direction of axis 678, will be at least 3 times(typically at least 4 times) the axial length of the bypass filter media694 section 618.

Lower end cap 695 is provided with an optional outwardly directed lip698, positioned such that, when serviceable filter cartridge 615 isdrawn upwardly through housing 603. The lip 698 can catch sediment inannular volume 633, FIG. 11, for removal from assembly 601.

From the previous descriptions, and a review of FIG. 11, it can be seenthat during a servicing operation, cover 605 would be removed, and theserviceable filter cartridge 615, comprising the primary filtercartridge 617 and the bypass filter 618, would be operably installed andcover 605 would be positioned in place.

Proper operation of the bypass filter 618, is controlled by the bypassvalve assembly 625. Referring to FIG. 12, the bypass valve assembly 625comprises a valve member 700, in this instance a tubular valve member701 slidably positioned within seat 702 between biasing member 705 (inthis instance spring 705 a) and stop 706. Sufficient fluid pressureagainst region 707 will cause the bypass valve 625 to open. In thisexample, the valve member 700 and spring 705 a are mounted withininternal valve frame piece 900. The valve frame piece 900 includes anddefines seat 702.

The valve frame piece 900, mounted on housing 603, supports: bypassvalve assembly 625; suction filter assembly 610; and, flow regulationcontrol assembly 647.

Attention is directed to FIGS. 21-23, with respect to valve frame piece900. In FIG. 21, valve frame piece 900 is depicted in an orientationsimilar to that it would have, when installed on the housing 603 of thearrangement 601 of FIG. 11. In FIG. 23, piece 900 is depicted incross-sectional view, with a similar orientation. In FIG. 22, framepiece 900 is viewed inverted, relative to FIGS. 21 and 23.

As indicated, the valve frame piece 900 is involved in a number ofoperations. In this next portion of the description, detail will beprovided with respect to:

-   -   1. How internal structural piece 900 is secured to and sealed        within housing sidewall 607;    -   2. How internal structural piece 900 is sealed to filter        cartridge 615; and,    -   3. How internal frame piece 900, in conjunction with the biasing        member 705 and valve member 700 forms the bypass valve assembly        625.

Referring first to FIG. 21, frame piece 900 is tubular and has oppositeopen ends 901, 902. At end 902 internal cross framework 903, discussedbelow, is provided.

Spaced between ends 901 and 902, is provided a radial ring definingperipheral seal support member 905, with an outer annular, peripheral,seal groove 906 therein. When valve frame piece 900 is mounted withinsidewall 607, an o-ring 908, FIG. 12, is typically positioned withingroove 906, for sealing against lower sidewall section 607 x. In atypical construction, the sidewall 607 would be pinched aroundprojection 905, to secure frame piece 900 in position.

Seal support member 905 generally separates the frame piece 900 into twosections, 900 a and 900 b. Referring to FIG. 11, portion 900 a generallyprojects axially into an interior of side wall 607, when mounted, andsection 900 b generally projects axially outwardly from side wall 607,when mounted.

Referring again to FIG. 21, immediately adjacent end 901, section 900 aof valve frame piece 900 defines outer seal surface 910. The sealsurface 910 is sized and configured to be received within lip or slot697, FIG. 20, on end cap 688 during use; sealing between valve framepiece 900 and end cap 688 being provided by o-ring 688 b, FIG. 20.Sidewall portion 911, FIG. 21, then, is sized to be positioned betweenprojection 688 a and bypass filter media 694, during installation.Again, sealing is preferably along inside surface 910, althoughalternate configurations are possible.

Referring to FIG. 23, interior volume 920 of internal frame piece 900,is sized for receipt of components of the bypass valve assembly 625therein, in particular valve member 701 and biasing member 705 a. Thebiasing member or spring 705 a would be seated at seat 921, FIG. 23, andit would extend upwardly. The valve member 701 would be slideablyreceived between the spring 705 and stop or seat 706, FIG. 12. The stop706 would comprise a snap ring positioned in groove 706 a, FIG. 23,after insertion of the spring 705 and slide member 701 through end 901during assembly.

Bypass valve aperture arrangement 925, in side wall section 900 a,provides for a communicating flow between volume 635 and volume 633,FIG. 12, for pressure to be applied against tubular valve member 701.When this pressure differential between regions 633 and 635 exceeds adefined amount, the biasing force of spring 705 a is overcome, tubularvalve member 701 slides away from seat 702, and aperture arrangement 925is opened so that a bypass flow can go from region 633, FIG. 12, intoopen region or interior 930 of internal frame piece 900. From here theliquid can, depending on circumstances, flow to the outlet arrangement631, or through end 642, FIG. 11, to the tank.

Assembly 601, analogously to assembly 1, includes a flow/pressureregulation valve assembly. In the instance of assembly 601, theflow/pressure regulation valve assembly is indicated at 647, FIG. 11,and controls flow through end 642. Referring to FIG. 12, end 642 is end902 of section 900 b (FIG. 23) of valve frame piece 900.

In operation, FIG. 11, flow through end 648 is inhibited by disk-shapedvalve member 751, until pressure in region 930 exceeds the controlpressure of spring 940. At this point, the valve member 751 will move toopen aperture arrangement 902 a at 902 to liquid flow therefrom, andinto the tank. That is, under the appropriate pressure conditions withinregion 930, liquid flow can go through end 642, FIG. 11, to the tank.This will be understood in further detail by reference to FIGS. 27 and28.

In FIG. 27, frame piece 900 is depicted with member 751 mounted thereon.More specifically, at end 902, frame piece 900 includes aperture 902 a.Valve member 751 is sized and positioned to seek and close aperture 902a. Valve member 751 is mounted on slideable post 941, and is securedthereto by nut 942. The post 941 and end 943 includes flange 944. Post941 is secured under pressure by spring 940 a between flange 944 andseat 945. The spring 940 a is configured to allow the valve member 751to move out of the seat closing aperture 902 a, under a pressure withinregion 930 as desired or set, by the manufacturer. As with thearrangement of FIG. 1, a typical opening pressure would be on the orderof 0.5 bar (0.3-0.7 bar). In FIG. 28, valve member 751 is shown biasedopen, to allow flow passage through aperture 902 a.

Attention is directed to FIGS. 24-26, in which a subassembly comprisingthe suction filter arrangement 610 is depicted. Suction filterarrangement 610 comprises media 770 extending between end caps 771, 772,FIG. 25. It can be seen, in FIG. 25, that around the outside of themedia 770, is provided a space 773 between end caps 771, 772.

The suction filter arrangement 610 includes, positioned within space773, directionally biased valve arrangement 664. The directionallybiased valve arrangement 664 comprises a ring 775 having cat (flap)valves 776 thereon. The flap valves 776 are oriented to open by pivotingtoward axis 780, FIG. 25, and away from opening 664 a, FIG. 25.

In FIG. 29, the directionally biased valve arrangement 664 is showncomprising ring 775, with flap valves 776 thereon. In FIG. 29, flapvalves 776 are shown biased open. The directionally biased valvearrangement 664 also includes an outer support ring 780 includingapertures 781. When assembled, the ring 775 will be positioned withinthe support ring 780, with the flaps 776 oriented aligned with aperture781. To facilitate operation, ring 775 would typically comprise anannealed material.

It is noted that in FIG. 29, ring 775 is shown as a continuous circularpiece. It can also be formed from a coiled strip, with an open gap orseam between opposite two ends, as shown for the embodiment of FIGS.1-9.

The subassembly 654, FIGS. 24-26, is mounted within assembly 601, and onthe housing 603 as shown in FIG. 12, with sealing by o-rings 950 xagainst valve frame piece 900 and is held in place by ring 951. Ofcourse, mounting of the valve frame piece 900 on side wall 607 wasdescribed above.

The media 770 would typically comprise a cylindrical wire mesh orplastic mesh media, typically pleated, supported by a porous inner liner785. A variety of alternate media arrangements can be used for the media770, including for example non-woven media of cellulose synthetic orglass fibers. The choice of media would typically be made for theparticular environment of use. However for a typical environmentinvolving hydraulic fluids, the intake filter assembly would typicallyuse a wire mesh or plastic mesh screen.

The end caps 771, 772 can be metal, or they are molded from a polymericmaterial, such as a polyamide, typically a glass-filled (for example15-30% glass filled, by wt.) polyamide. They can be conveniently securedto the media 770.

Referring to FIG. 12, in general should the pressure and region 633, orflow demands in that region, require in flow from the tank, flap valves776 of ring 775 will pivot inwardly, allowing liquid flow to be drawninto suction filter 610, through media 770 and into central region 790of the suction filter 610. The liquid can then be drawn up into region633 and be directed outwardly through outlet arrangement 633, FIGS. 10,11, as appropriate.

Attention is now directed to FIG. 13, which, analogously to FIG. 2,shows general operation of the assembly 601. Referring to FIG. 13, theinlet arrangement is shown at 630, comprising two inlet ports A1, A2(inlet port A2 being optionally used or capped).

At 617, the main filter assembly is shown, with filtered liquid beingcirculated for outlet arrangement 633, comprising outlet lines B1, B2(optionally one of lines B1 and B2 being capped). The bypass filter 618is viewable, receiving liquid from inlet 630, if appropriate, controlledby bypass valve arrangement 625. Liquid which goes through bypass valveassembly 625 can be directed through outlet 633, as shown.

At 647, the flow regulation valve arrangement is shown, allowing forselected flow into tank 950. Draw from tank 950 is shown going throughsuction filter arrangement 610 comprising valve ring 675 and media 770.

The major differences between the flow chart of FIG. 13, and the flowchart of FIG. 2, are:

-   -   1. In the suction filter arrangement 610, FIG. 13, the valve        arrangement 675 is positioned around the media 770. That is, the        valve member 675 is positioned between the media 770 and the        tank 950; and    -   2. The inlet arrangement 630 and outlet arrangement 633 are        depicted with optional second lines.

The following dimensions will be useable in understanding howarrangements utilizing the principles of FIGS. 10-26, can be implementedfor in-tank arrangements having flows therethrough of, for example, upto 250 liters per minute.

Total length of unit, FIG. 10, from top of cover handle to bottom lid:370 mm, for about 200 liter/minute operation, 445 mm for about 250liter/minute operation. Length of unit from bottom edge of filter head604 to lower end of bypass filter: 316 mm for about 200 liter/minuteoperation, 382 mm for about 250 liter/minute operation.

The following dimensions are reasonable for an element for up to 200liter/min. operation: Outside diameter suction filter—100 mm; outsidediameter of tubular valve member for bypass valve—50 mm; total length oftubular bypass valve member—17 mm; inside diameter of tubular bypassvalve member 42 mm; total length of service cartridge about 370 mm;outside diameter of third end cap with outwardly projecting lip 698,FIG. 12—97.2 mm; total axial length of valve frame piece 900, FIGS.21-23—95.2 mm; inside diameter of aperture at end 901, FIG. 21—50 mm;outside diameter of seal support 905, FIG. 23—96 mm; total length ofhousing side wall 607—339 mm; outside diameter of suction filter, FIGS.24-26—99 mm; total height of suction filter assembly 610, FIGS. 24 and25—46.2 mm; total height of opening 664 a, FIG. 25—29 mm. The dimensionscan be varied. For optimization for specific selected systems, the aboveprovide an example or guide, from which to work toward optimizeddimensions.

Other dimensions can be calculated for scale, or be determined based ona specific application.

What is claimed is:
 1. A liquid filter assembly comprising: (a) ahousing defining an interior and having: a liquid flow inletarrangement; a first circulation loop liquid flow outlet arrangement;and, a tank reservoir liquid flow inlet/outlet; and, (b) a suctionfilter assembly secured to the housing of the liquid filter assembly andpositioned in a liquid flow communication with the reservoir liquid flowinlet/outlet; the suction filter assembly including: (i) an extension ofsuction filter media surrounding and defining a suction filter mediacentral volume; and, (ii) a first, non-helical spring, directionallybiased valve arrangement comprising a ring shaped valve member having atleast one cut valve therein positioned and configured to: (A) readilypermit liquid flow from a tank reservoir through the suction filtermedia and into the housing interior; and, (B) to resist liquid flow fromthe housing interior, through the suction filter media and then into thetank reservoir.
 2. A liquid filter assembly according to claim 1wherein: (a) the ring-shaped valve member has a plurality of flap valvestherein and defines an internal volume.
 3. A liquid filter assemblyaccording to claim 2 wherein: (a) each flap valve is a u-shaped flapvalve positioned to point around a central axis of the suction filterassembly.
 4. A liquid filter assembly according to claim 1 including:(a) a flow/pressure regulation valve positioned to regulate flow fromwithin the housing into the tank reservoir.
 5. A liquid filter assemblyaccording to claim 4 wherein: (a) the flow/pressure regulation valvecomprises: a valve seat having an aperture therein; a valve member; and,a biasing member.
 6. A liquid filter assembly according to claim 5wherein: (a) the flow/pressure regulation valve comprises a slidablevalve member; (i) the slidable valve member of the flow/pressureregulation valve being selectively biased, by the biasing member, intosealing relation with the valve seat; (ii) the valve seat of theflow/pressure regulation valve being positioned between the slidablevalve member of the flow/pressure regulation valve and the internalvolume defined by the ring-shaped valve member of the first, non-helicalspring, directionally biased valve arrangement.
 7. A liquid filterassembly according to claim 6 wherein: (a) the first, non-helicalspring, directionally biased valve arrangement is surrounded by theextension of suction filter media.
 8. A liquid filter assembly accordingto claim 5 wherein: (a) the flow/pressure regulation valve comprises:(i) a valve frame piece having opposite ends and a central flowpassageway extending therebetween; (A) a first end of the frame piecehaving an end aperture and an outer seal surface for a serviceablefilter cartridge; and, (B) a second end of the frame piece, opposite thefirst end, having an aperture defining the valve seat of theflow/pressure regulation valve.
 9. A liquid filter assembly according toclaim 8 wherein: (a) the suction filter media is surrounded by thefirst, non-helical spring, directionally biased valve arrangement.
 10. Aliquid filter assembly according to claim 5 wherein: (a) the suctionfilter media is cylindrical.
 11. A liquid filter assembly according toclaim 5 wherein: (a) the suction filter media is secured to a valve frompiece and the valve frame piece is secured to the housing side wall. 12.A liquid filter assembly according to claim 1 wherein: (a) the housingcomprises: a filter head; and, a housing side wall; (i) the filter headincluding: (A) a filter head body; (B) a top cover removable from thefilter head body to define a service opening in the filter head; (C) abottom aperture positioned opposite the openable top cover and serviceopening; (D) the first circulation loop liquid flow outlet arrangement;and, (E) the circulation loop liquid flow inlet arrangement; and, (ii)the housing side wall being positioned to extend through the bottomaperture in a direction opposite the top cover; (A) the suction filterassembly being positioned at an end of the housing sidewall opposite thefilter head.
 13. A liquid filter assembly according to claim 12 wherein:(a) the housing side wall is removeably secured to the filter head; and,(b) the housing side wall and suction filter assembly are sized to beinstalled by projection through the service opening and the bottomaperture in the filter head body, when the openable top cover isremoved.
 14. A liquid filter assembly according to claim 12 including:(a) a serviceable filter cartridge positioned with at least a portionthereof projecting into the interior of the housing; (i) the serviceablefilter cartridge being sized to be inserted through, or removed from,the service opening when the top cover is removed from the filter headbody; (ii) the serviceable filter cartridge including: a primary filtermedia section defining a central axis and having opposite ends; and, abypass filter media section secured to, and separated from, the primaryfilter media section by a first end cap.
 15. A liquid filter assemblyaccording to claim 14 wherein: (a) the filter cartridge includes asecond end cap secured to an end of the primary filter media sectionopposite an end to which the first filter end cap is secured; (i) thesecond end cap having a seal projection thereon configured to define aseal plane extending at a non-orthogonal angle to the central axis ofthe primary filter media section.
 16. A liquid filter assembly accordingto claim 15 including: (a) a stand pipe secured within the housing sidewall at a position with at least a portion of the stand pipe surroundedby at least a portion of the primary media section and a portion of thestand pipe surrounded by at least a portion of the bypass filter mediasection; (i) the first end cap of the filter cartridge being sealed tothe stand pipe to define: (A) an upper stand pipe section surrounded bythe primary filter media section; and (B) a lower stand pipe sectionsurrounded by the bypass filter media section and separated from theupper stand pipe section by the seal between the filter cartridge firstend cap and the stand pipe; (ii) the stand pipe having a central flowinterior in non-filtering liquid flow communication with both: thecirculation loop liquid flow outlet; and, the reservoir liquid flowinlet/outlet; and, (b) a bypass valve arrangement positioned within thelower stand pipe section to selectively permit liquid flow through thebypass media section and into the flow interior of the stand pipe, bypassage through the lower stand pipe section, in response to a bypassvalve opening liquid pressure caused by occlusion of the primary filtermedia section.
 17. A liquid filter assembly according to claim 16wherein: (a) the bypass valve arrangement comprises: (i) a tubular valvemember slidably received within the lower stand pipe section andslideable between an open orientation and a closed orientation; and,(ii) a biasing member position to bias the tubular valve member to aclosed orientation until the bypass valve opening liquid pressure isreached.
 18. A liquid filter assembly according to claim 14 including:(a) a valve frame piece secured to an end of the housing sidewall; (i)the valve frame piece comprising a tubular member having first andsecond ends; (ii) the valve frame piece including a central mountingring thereon; (A) the valve frame piece being secured in place with thecentral mounting ring in engagement with the housing sidewall with: afirst portion of the valve frame piece, on a first side of the centralring, projecting into an interior of the housing side wall; and a secondportion of the valve frame piece, on a second side of the central ring,projecting axially outwardly from the housing side wall; (iii) the firstportion of the valve frame piece having a bypass flow aperturearrangement therein; and (b) the bypass valve arrangement includes atubular valve member positioned within the first portion of the valveframe member and secured in covering relation to the bypass flowaperture arrangement by a bypass valve biasing member until the bypassvalve opening pressure is reached; and (c) a flow/pressure regulationvalve arrangement including a flow/pressure regulation control valvemember operably positioned over the second end of the valve frame piece.